The V&A archive (ACGB/51/1265) contains the accounts for the 1964 and 1965 summer schools and a budget for the 1965 event. I have posted the 1964 accounts here.

One of my research questions considers ways in which these summer schools were funded, and how this reflects prestige, as well as indicating the priorities of the events. Here is the budget for the 1965 events.